Process of refining wood-alcohol.



a mixture UNITED STATES LEE F. HAWLEY, OF BOSTON, MASSACHUSETTS, ASSIGINOR TO ARTHUR D. LITTLE, 1150.,

' BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

rnoonss or anrimuc WOOD-ALCOHOL.

1,106,7407. m'nrawing.

I Specification of Letters Patent. Application filed April 13, 1914. Serial No. $31,582.

Patented Aug. ilil, Jlfillt.

To all whom it ma concern Be it known t at'I, LEE F. HAWLEY, a

lig'neous materials, and containing methyl alcohol and acetone.

In the distillation of crude wood alcohol for the production of methyl alcohol or refined wood alcohol, much difliculty is encountered in the separation from the methyl alcohol of the other principal constituent of the crude alcohol, viz., acetone. Not only do these two liquids have boiling-points close together in the temperature scale, but they also form a constant-boiling mixture, so that their complete separation by distillation alone is impossible. In practice, therefore, it is not attempted to recover pure acetone, but two main products are produced, to wit,

sometimes called methylacetone which contains only about 50 per cent of acetone; and a refined wood alcohol contains from 0.1 per cent. to ten per cent. of acetone. The relative proportions in which these two products are obtained depends upon their relative composition, and on the efliciency of the fractionation.

According to the present invention, it be comes possible to separate the fraction high in acetone the so-called methyl-acetone? of commerce, into (1) acetone, entirely free from alcohol, and (2) a mixture of alcohol and acetone so high in alcohol that it can be sent back and included 'in the distillation process without interfering with the latter. By proceeding in thismanner, the two final products are acetone nearly or quite free from alcohol, and alcohol containing only a very small variable amount of acetone, according to the efficiency of the distillation process.

The production of acetone .free from alcohol in accordance with the present invention depends on the fact that methyl alcohol is readily soluble in aqueous soluwhile acetone is relatively insoluble in such solutions, so that when the proper proportlons of alcohol, acetone, water, and sodium or potassium hydroxidare brought together two liquid layers or strata are formed, 0

which the upper contains arelatively large proportion of acetone while the lower contains relatively large proportions of alcohol dissolved in the aqueous caustic alkali. Satisfactory separation Y of alcohol and acetone often can not beobtained bya sin le treatment of this kind, but by means 0% a short series of treatments in which the lower or alkaline layer from one treatment is added to the upper layer from a preceding treatment, and so forth, it is possible to obtain at one end of the series an acetone free from alcohol, and at the other end of the series an alcohol containing only a small proportion of acetone.

The following is a concrete, illustrative example ofa process in accordance with my invention, this example showing the com bination of such a fractional solution process with fractional distillation for the complete refining of crude wood alcohol: 100 parts of crude wood alcohol containing 85 per cent. of alcohol and acetone, in a ratio of about 4: to 1', are separated by fractional distillation into three fractions, viz.: (1) 35 parts of so-called methyl-acetone containing about 50 per cent. of acetone; (2) 50 parts of a refined methyl alcohol consisting of 98 per cent. alcohol and 2 per cent. acetone; (3) 15 parts of water, allyl alcohol, wood oils, and other impurities.

The methyl-acetone fraction (1) is treated with caustic soda solution in a series of four washings, of which the first washing is with a caustic soda solution which has been used three times before; the second with a solution used twice before; the third with a solution used once before; and the fourth with a fresh caustic soda solution of about thirty per cent. concentration and in volume about equal to the original methyl-acetone treated. The final upper layer after this series of washings, consists of acetone and water quite free from either alcohol or caustic soda, and

amount of water which can be returned to the original distillation refining process, and (2) a solution of caustic soda which can be used again in the treatment of another lot of methyl-acetone. It is to be understood that other quantities and compositions of materials, and other numbers of washings may be used, depending on conditions, including the quality of refined alcohol which it is desired to produce and the efiiciency of the refining still; or, if desired, the alcohol-acetone mixture may be marketed without further refining.

I claim z- -1. In a process of refining crude wood alcohol containing acetone, the step which .consists in effecting a separation of a layer rich in acetone by means of alkali, and sub jecting said layer to a further refining process.

2. In a process of refining crude wood alcohol, the steps which consist in subjecting a mixture containing methyl alcohol and acetone to repeated fractional solution with aqueous alkali, under conditions to obtain an acetone-containing layer substantially and an alcohol-containing free from alcoho layer low in acetone.

3. The method of separating acetone from I mixtures thereof with methyl alcohol, which consists in stratifying the mixture by addi tion of alkali, and purifying the stratum richer in acetone by dissolving the residual alcohol therefrom.

' 4. The method of separating acetone from mixtures thereof with methyl alcohol, which consists in stratifying the mixture by addition of alkali, and purifying the stratum richer in acetone by dissolving the residual alcohol therefrom by means of an aqueous solution of alkali.

5. The method of separating acetone from mixtures thereof with methyl alcohol, which consists in stratifying the mixture by addithe particularmethyl alcohol from methyl tion of alkali, and purifying the stratum richer in acetone by dissolving the residual alcohol'therefrom by successive treatments with aqueous solutions of alkali.

6. The method of separating acetone from mlxtures thereof with methyl alcohol, which consists in fractionally dissolving alcohol from the mixture by successive treatments with caustic alkali solutions previousl used for treating similar mixtures, and e ecting a final purification by caustic alkali free from alcohol.

7. The method of refining crude wood alcohol, which consists in fractionally distilling the same, fractionally dissolving methyl alcohol from the distillation'fracti'on highest in acetone by means of aqueous solutions of alkali, distilling the resulting solution of methyl alcohol, and returning the distillate to the fractional distillation process.

8. The method of recovering acetone and mixtures thereof,

which consists in dissolvin the alcohol in aqueous caustic alkali, col ecting and distilling the acetone, and distilling the alkaline alcoholic solution forthe recovery of alcohol low in acetone and an aqueous alkaline solution in condition for re-use.

49. The method of recovering acetone and alcohol from mixtures thereof, which consists in fractionally dissolving the alcohol in successive portions of aqueous alkali, collecting and distilling the acetone, and distilling the for the recovery of alcohol low in acetone and an aqueous alkaline solution in condition for re-use,

In testimony whereof I aflix my signature in presence of two witnesses.

7 LEE F. HAWLEY. Witnesses:

CHAS. M. BULLARD, ARTHUR O. SPIERLING. 

